Corinnomma lawrencei, Haddad, 2006

Haddad, Charles R., 2006, A new species of Corinnomma (Araneae: Corinnidae) from southern and eastern Africa, with taxonomic notes on C. olivaceum and C. semiglabrum, African Invertebrates 47, pp. 71-83 : 77-80

Corinnomma lawrencei sp. n.

Figs 2 , 10–15

Etymology: This species is named in honour of Dr R.F. Lawrence, prominent arachnologist of the last century and collector of part of the type series.

Diagnosis: This species is distinguished from others in the genus by the small epigyne and the medially directed entrance ducts. Judging from epigyne shape, C. lawrencei appears most closely related to C. thorelli Simon, 1905 . It can be distinguished by the distinct separation of the terminal receptaculae of the spermathecae, which are directed medially; those of C. thorelli lie against each other and are directed laterally (Deeleman-Reinhold 2001).

Description:

Female.

Measurements: CL 3.40–3.85, CW 2.15–2.30, AL 3.60–4.10, AW 2.40–2.70, TL 7.40– 8.10, FL 0.35–0.40, SL 1.60–1.78, SW 1.13–1.20. Interdistances between eyes: AME– AME 0.13, AME–ALE 0.07, ALE–ALE 0.52, PME–PME 0.23, PME–PLE 0.20, PLE– PLE 0.83.

Length of leg segments (sequence from femur to tarsus, and total): I 2.35+0.88+ 2.30+1.90+1.35=8.78; II 2.23+0.85+1.88+1.68+1.20=7.84; III 2.00+0.90+1.68+1.78+ 0.93=7.29; III 3.00+1.15+2.80+3.05+1.15=11.15.

Cephalothorax: Carapace dark brown to nearly black, finely wrinkled, clothed in very short white setae; elongate, broadest at midpoint ( Fig. 10 ); highest at nearly one-third its length ( Fig. 11 ). Fovea distinct, located slightly posterior to carapace midpoint; striae black, radiating outwards from fovea, fused to black markings laterally on carapace.AER straight, median eyes larger; PER slightly recurved, eyes similar in size; all eyes surrounded by black rings; scattered white plumose setae on clypeus. Chelicerae bulging slightly ( Fig. 11 ), dark brown; long, pale setae on prolateral margin with scattered short white setae between; two teeth on promargin, proximal tooth bifid with single base; two simple teeth on retromargin.Sternum dark brown, nearly black, with faint black mottling; surface slightly granular; densely clothed with short white setae medially, and longer white setae near margins; single long erect black seta on sternum near each coxal base.

Legs: Femora I dark brown to black in proximal half, yellow distally; dark brown do stripe extending to end of femora; femur II entirely black dorsally, yellow at distal end; femora III and IV dark brown, with yellow marking pl at distal end. Patella I and II yellow with dark brown plv and rlv stripes; patellae III and IV dark brown. Tibiae I and II yellow dorsally with brown median stripe, yellow ventrally with brown plv and rlv stripes; tibiae III and IV dark brown.All metatarsi brown, with yellow distal tips.All tarsi orange-brown, darker in do proximal half; black markings on legs comprising plumose setae. Leg spination as follows: femora: I pl 1 do 3, II do 3, III pl 2 do 3 rl 1, IV pl 2 do 3 rl 1; patellae: all patellae with distal do tr; tibiae: I plv 3 rlv 1–2, II plv 1–2 rlv 1–2, III pl 2 do 1 rl 2 plv 2 rlv 1 vt 2, IV pl 2 do 1 rl 2 plv 2 rlv 1 vt 2; metatarsi: I plv 2 rlv 2, II plv 2 rlv 2, III pl 3 rl 3 plv 2 rlv 2 vt 3, IV pl 3 rl 3 plv 2 rlv 2 vt 3. Palp dark brown, nearly black. Femora: pl 1 do 2, rlv 4; patellae pl 1 do 1; tibiae pl 2 do 2; tarsi pl 1 do 1 rl 1. Single small terminal pectinate claw. Abdomen: Oval, slightly globose, integument grey, broadest at two-thirds its length; leathery dorsal scutum present, dark red-brown, narrow, extending to two-thirds abdomen length; inframamillary sclerite absent; dorsum densely covered with short white setae; four black bands comprising plumose setae; first at front of abdomen, extending to epigastric sclerite; second at one-sixth abdomen length and third at one-third abdomen length, both fusing laterally at third band; fourth band broadest, extending from half to two-thirds abdomen length ( Fig. 11 ). Genitalic area and booklungs dark red-brown to nearly black, strongly sclerotised. Epigyne with copulatory openings situated laterally ( Fig. 12 ), approximately at midpoint of epigyne; entrance ducts initially directed medially, curving upwards to spermathecae ( Fig. 12 ). Spermathecae round with bean-shaped terminal receptaculae ( Fig. 13 ).

Male.

Measurements: CL 2.70–2.90, CW 1.75–1.83, AL 2.90–3.00, AW 1.50–1.60, TL 5.80– 5.95, FL 0.25–0.28, SL 1.20–1.23, SW 3.55–3.60. Interdistances between eyes: AME– AME 0.10, AME–ALE 0.05, ALE–ALE 0.39, PME–PME 0.17, PME–PLE 0.14, PLE– PLE 0.64.

Length of leg segments (sequence from femur to tarsus, and total): I 1.83+0.63+1.78+ 1.70+1.33=7.27; II 1.60+0.70+1.43+1.45+1.05=6.23; III 1.48+0.68+1.28+1.55+ 0.80=5.79; IV 2.48+0.88+2.23+2.70+1.05=9.34.

General habitus similar to female described above; male less robust than female; abdomen elongate and narrow, broadest at three-quarters its length; dorsal scutum covering entire dorsum; inframamillary sclerite present, rectangular, extending from epigastric furrow to in front of spinnerets.

Legs: markings on legs less distinct than for female. Leg spination as follows: femora: I pl 1 do 3, II do 3, III pl 2 do 3 rl 1–2, IV pl 2 do 3 rl 1; patellae: all with 1 distal dtr; tibiae: I plv 2 rlv 1, II plv 2 rlv 1, III pl 2 do 1 rl 2 plv 2 rlv 1 vt 2, IV pl 2 do 1 rl 2 plv 2 rlv 1 vt 2; metatarsi: I plv 2 rlv 2, II plv 2 rlv 2, III pl 3 rl 3 plv 2 rlv 2 vt 3, IV pl 3 rl 3 plv 2–3 rlv 2 vt 3; all tibiae and metatarsi with numerous dtr, increasing in size distally.

Male palp without retrolateral tibial apophysis; palpal tarsus compact; cymbium dark brown, paler distally; bulbus red-brown, rounded prolaterally; embolus prolaterally on bulbus, with short thin stalk and one and a half short compact coils ( Figs 2 , 14, 15 ); femur: pl 1 do 2; patella pl 1; tibia pl 2; tarsus pl 2, plv 1.

Holotype: ^‘ Mozambique / Maxixe, Inhambane / 23 ° 52'S 35 ° 23'E / Dec. 1923 / R. F. Lawrence // Clubionidae / South African Museum / Cape Town / B7159 //’ ( SAMC B7159 ).

Paratypes: 1^same data and depository as holotype. 2ơ 2^‘ R . S.A., Ndumo Game Reserve / Pongola River Floodplain / 26 ° 53'21.7"S 32 ° 18'53.5"E / 09.II.2005 / C. Haddad (Leaf litter) //’ ( NCA 2005 /45) .

Other material examined: 1 juvenile same data and depository as holotype. SOUTH AFRICA: Limpopo: 2ơ 1^Lajuma, Short Forest 3, 23º02.165'S: 29º26.985'E, 27.xi.2004, active searching, M. Mafadza ( NCA 2005 /2018); 2ơ same locality, Short Forest 4, 23º02.388'S: 29º26.398'E, 27.xi.2004, active searching, M. Mafadza ( NCA 2005 /2017). TANZANIA: 1^Udzungwa Mountain National Park , x.2001, hand collecting, G. Callaham ( NCA 2005 /2030) .

Distribution: Found in the eastern regions of Tanzania, Mozambique and South Africa. Biology: This species was found near a nest of Anoplolepis custodiens ants in Ndumo Game Reserve, together with C. semiglabrum , a Castianeira species, Merenius alberti Lessert, 1923 and P. gagates ants, which it mimics. Initial feeding trials in the laboratory with two male C. lawrencei indicate that they do not feed on workers of A. custodiens or P. gagates , and within the restricted confines of a Petri dish, both spiders were badly injured by the ants, losing several legs. This species is almost identical to C. semiglabrum in general appearance, and the two species can only be separated by genitalic and eye characteristics. Adaptations for mimicry of P. gagates are similar to those described for C. semiglabrum above.

Figures

Figs 1, 2. Scanning electron micrographs of male emboli of Afrotropical Corinnomma species: (1) C. semiglabrum (Simon); (2) C. lawrencei sp. n.

Figs 10–15. Corinnomma lawrencei sp. n., paratypes: (10, 11) female cephalothorax, dorsal and lateral views; (12) female (Inhambane), epigyne, ventral view; (13) female (Inhambane), vulva, dorsal view; (14, 15) male (Ndumo), left palp, ventral and retrolateral views. Scale bars: Figs 10, 11 = 1.0 mm; Figs 12–15 = 0.25 mm.